Cylinder head for internal combustion engines



Dec.24, 1935. F. GOSSLAU I 2,025,506

CYLINDER HEAD FOR INTERNAL COMBUSTION ENGINES Filed Jan. 25, 1932 4 Shets-Sheet l 8 4 77 7 l H l h l h. h l 7 I ,g

De 24, 1935. GQSSLAU 2,025,506

CYLINDER HEAD FOR INTERNAL COMBUSTION ENGINES Filed Jan. 23, 1932 4 Sheets-Sheet 2 Dec. 24, 1935. I GOSSLAU 2,025,506

\ CYLINDER HEAD FOR INTERNAL COMBUSTION ENGINES Filed Jan. 23, 1932 4 Sheets-Sheet 3 Dec. 24,- 1935. GQSSLAU 2025506 CYLINDER HEAD FOR INTERNAL COMBUSTION ENGINES Filed :Ian. 23, 1932 4 Sheets-Sheet 4 Patented Dec. 24, 1935 PATENT OFFICE CYLINDER HEAD FOR INTERNAL COMBUSTION ENGINES Fritz Gosslau, Berlin-Charlottenburg,

Germany,

assignor to Siemens & Halske, Aktiengesellschaft, Siemensstadt, near Berlin,

Germany, a

corporation of Germany Application January 23, 1932, Serial No. 588,359 In Germany January 27, 1931 6 Claims.

My invention relates to improvements in internal combustion engines, and more particularly to cylinder heads of radial stationary cylinder air-cooled aeroengines provided with a streamlined cowl.

Stationary radial cylinder air-cooled aeroengines as compared to tandem cylinder watercooled internal combustion engines are often considered as being inferior owing to the great air resistance. The air resistance of stationary radial cylinder air-cooled aeroengines has been successfully reduced lately, by providing around the cylinder heads a ring having a supporting surface of wing-like cross-section.

Further tests have, however, proven that in some cases it may be convenient, especially in engines with less than seven cylinders to provide each cylinder head with a stream-line cap or cowl. This has been, hitherto, accomplished by providing each cylinder with standard circular cast-on cooling fins or ribs with stream-line cowls made of sheet iron. The design of such cowls was, as a rule, left in the hands of the aeroplane designer, rather than in those of the engine designer. Consequently, the most favorable conditions for the cooling at the least air resistance could not beattained in a perfect manner.

The drawbacks of the prior stream-line caps or cowls of the individual cylinders are avoided in accordance with my invention by applying the cowls to the cylinders in such a manner as to transfer the heat by conduction to the surfaces being cooled by the external of the stream-line cowl directly fitted to the' cylinder as well as to the cowl from the interior through the action of a fluid medium, said cowl air flowing alongside the same.

In the drawings which show by way of illustration three embodiments of the invention,

Fig. 1 represents one embodiment in sectional elevation on line l-l in Fig. 2.

Fig. 2 represents a transverse section through Fig. 1 on line 2-2 in Fig. 1.

Fig. 3 represents a front elevation of Fig. 1.

Fig. 4 represents a full side elevation of Fig. 1.

Fig. 5 represents a top view of Fig. 1.

Figs. 6 and 7 represent a sectional elevation and a transverse section respectively of a further embodiment.

, Fig. 8 represents the installation in an aeroplane of an engine with cylinders designed according to the embodiment Figs. 6 and 7, and

Flgs.9 and 10 represent a cylinder of a third embodiment in side elevation, partly in sectional.

elevation, Fig. 10 showing the installation in an aeroplane;

In the embodiment shown in Figures 1-5, the cylinder head I with the cooling fins 2 and 3 and the cowl 4 and the extensions 5 and 6 are made 5 of one piece. The cowl 4 is provided with an opening 1 through which the cooling air flows. The cooling ribs 8, rising from the cylinder head in the direction of its central axis, extend in the direction of the cowl and thus form channels 8 10 through which the cooling air streams. The cooling-fins 2 in the front and on both sides of the cylinder head serve to'increase the cooling surface of the cylinder head I, and are rearwardly extended in the form of the stream-line walls 5 and 6. Between these extension walls, 1. e. on the trailing side of the cylinder, cooling fins 3 are disposed which run in parallel relation to the I generatrix of the cylinder. The extensions Ii and 6 form together with a guide plate 9 and the rear wall of the cylinder head a passage III which at the edge of transverse rib l3 joins the portion ll of the cowl interior in which portion the individual channels 8*. aforementioned terminate, the total amount of cooling medium thus col-, lected being discharged through'the rear opening I! of the cowl. By such an arrangement cooling air is also directly conducted to the trailing portion of the cylinder head and thus an effective cooling of this part of the cylinder jacket, where the hot air has hitherto undesirably accumulated is attained.

By extending the transverse rib l3 a sufllcient distance toward the discharge opening II, as shown, so that the air currents travelling upwardly through duct Ill are deflected toward opening l2, a sufiicient suction efiect is produced by the strong currents flowing over the cylinder head, to draw a considerable amount of air through 'duct l0 and past fins 3 so as to make 40 this cooling very effective.

Furthermore, it may be convenient not to dispose the cooling fins in parallel relation to the direction of flight but at an angle to the direction of flight in order to obtain a better suction effect of the air.

Also according to another embodlment'as disclosed in Figures 6, 7 and 8, the cylinder head I and the stream-line cowl 4 are made of one piece. The air in this case does not, however, flow through the cowl but exteriorly and alongside the same so that the resistance to flow is completely eliminated. In cross-section, a part of the cowl has completely the form of the cylinder I head. The cowl is fully -closed by the wall l4, 6!

and forms with the cylinder the hollow spaces l5 and I6. To facilitate the transmission of heat, the hollow spaces are filled up with a heat transmitting fluid medium. For this purpose, such substances as ethylenglycole, glycerin, oil or metallic salts are suitable which liqueiy at a higher temperature. By reason of the different temperatures prevailing in the cylinder and cowl, the substances are caused to circulate, thereby transferring the heat from the cylinder to the walls of the cowl exposed to the cooling air.

Figure 8 shows a cylinder, provided with a streamline cowl according to Figures 6 and '7 projecting from the body of the aeroplane, and which is exposed to that extent to the cooling air. II

denotes the propeller of the aeroplane.

Under certain conditions, it may also be convenient to provide the cowl with further cooling fins IE or ribs as will be seen from Figure '7 at the lower half.

In the embodiment shown in Figures 9 and 10, a passage I9 is provided on the trailing side of the cylinder, being'formed by the rear surface of the cylinder hood (similar to Fig. l) and by the wall 2| built integral with the cylinder hood 20. This passage is designed so as to cause the cooling air to fiow alongside of the cylinder hood on its trailing side and in the direction of its axis as far as the uppermost part of the cylinder hood. At this point it communicates with a further passage 22 formed by the stream-line wall 23, also built integral with the cylinder hood 20, and by the guide wall 2|. Through the passage 22, the cooling air is directed to the outlet 24 into the atmosphere.

Figure 10 shows the installation of the abovedescribed structure in an aeroplane. 25 denotes the fuselage, a supporting surface or another part of the aeroplane. During the flight the air flow occurs in the direction of the arrow 26, and the cooling air flows through special openings into the fuselage and bathes the lower part 21 of the cylinder. By reason of the pressure above atmospheric prevailing in this enclosure, the air is forced into the passage l9, thereby attaining the cooling action as described with reference to Figure 9. By this arrangement the width of the cylinder at right angles to the directionpf fiight may be maintained very small. In spite of the narrowness of the cylinder, an effective and intense cooling of the trailing side of the cylinder is secured by the air fiowln'g through the passage !9 as well as by the enlargement of the cooling surfaces through the guide walls 2| and 23, thus insuring the required radiation of heat.

On the trailing side of the cylinder, in a similar manner as shown at 3 in Figure 2, cooling fins l9 (Fig. 9) running substantially in the direction of medium flow in passage l9, may be arranged which subdivide the passage l9 into several canals which, in turn, terminate in the passage 22, thus obtaining a further enlargement of the cooling surfaces.

I claim as my invention:

1. In an internal combustion engine, means for cooling the cylinder by a cooling medium, comprising a cylinder head provided with a streamline cowl, attached to the cylinder head and forming with said head hollow spaces for the reception of the cooling medium, to carry off the heat from the cylinder by conduction as well as by absorption from said cylinder head, said cowl be"- ing exposed for cooling purposes to the external air streaming alongside the same, and being prO- vided with cooling fins on its outer periphery, said cowl forming with said cylinder head a passage having. walls gradually converging in the direction of medium flow, and extending above the cylinder head, said cowl having a further 5 wall forming together with the cylinder head a passage leading upwardly along the rear portion of the cylinder head, and terminating in the passage extending above the cylinder head, for directing cooling air'along. the rear wall of the 10 cylinder head by reason of the contracted design of the passage extended over the cylinder head.

2. In an internal combustion engine, means for cooling the cylinder by a cooling medium, comprising a cylinder head provided with a streamline cowl, attached to the cylinder head and forming with said head hollow spaces for the reception of the cooling medium, to carry oil? the heat from the cylinder by conduction as ,well as by absorption from said cylinder head, said cowl being exposed for cooling purposes to the external air streaming alongside the same, and being provided with cooling fins on its outer periphery, saidcowl forming with said cylinder head a; passage having walls gradually converging in the direction of medium flow, and extending above the cylinder head, said cowl having a further wall forming together with the cylinder head a passage leading upwardly along the rear portion of the cylinder head, and terminating in the passage extending above the cylinder head for directing cooling air to the rear wall of the cylinder head by reason of the contracted design of the passage extended over the cylinder head, said two passages being united at their ends to form a common outlet passage for the cooling air.

3. In an internal combustion engine, means for cooling the cylinder by a cooling medium, compriisng. a cylinder head provided with a streamline cowl, attached to the cylinder headand forming with said head hollow spaces for the reception of the cooling medium to carry off the heat from the cylinder head by conduction as well as by absorption from said cylinder head, said cowl being exposed for cooling purposes to the external air streaming alongside the same, and being provided with cooling fins on its outer periphery, said cowl forming a passage having walls gradually converging in the direction of the medium flow, and extending above the cylinder head, and an upwardly extending curved guide plate arranged at, and spaced away from the rear portion of the cylinder head between the lateral walls of the cowl, to form a further passage leading upwardly along the rear portion -01 the cylinder head, and terminating in the passage extending above the cylinder head for directing cooling air along the rear wall of the cylinder head by reason of the contracted design of the passage extending over the cyllnderhead, said two passages being united at their ends to form a common outlet passage for the cooling air.

4. In an internal combustion engine, means for cooling the cylinder by a cooling medium, com- 65 prising a cylinder head provided with a streamline cowl, attached to the cylinder head and forming with said head hollow spaces for the reception of the cooling medium, to carry off v the heat from the cylinder head by conduction as well as by absorption from said cylinder head, said cowl being exposed for cooling purposes to the external air streaming alongside the same, the lateral limiting surfaces. of said cowl being conducted tangentially to the wall of the cylinder head and being built integral with the cylinder head.

5. In an internal combustion engine, means for cooling the cylinder by a cooling medium, comprising a cylinder head provided with a streamline cowl, attached to the cylinder head and forming with said head hollow spaces for the reception of the cooling medium to carry off the heat from the cylinder by conduction as well as by absorption from said cylinder head, said cowl being exposed for cooling purposes to the external air streaming alongside the same, and being provided with cooling fins on its outer periphery, said cowl forming with said cylinder head a passage having lateral walls gradually converging in the direction of the medium flow, and extending above the cylinder head, and an upwardly extending curved guide plate arranged at, and spaced away from the trailing portion of the cylinder head between the lateral walls of the cowl, to form a trailing passage leading upwardly along the trailing portion of the cylinder head, and terminating in the passage extending over the cylinder head for directing cooling air along the trailing wall of the cylinder by reason of the contracted design of the passage extending over the cylinder head, said two passages being united at their ends to form a common outlet passage for the cooling air, and spaced cooling flns arranged in said trailing passage longitudinally thereof and extending transversely between the 5 cylinder wall and said curved guide plate.

6. In an intemalcombustion engine, means for cooling the cylinder by a cooling medium, comprising a cylinder head provided with a streamline cowl, attached to the cylinder head and forming with said head hollow spaces for the reception of the cooling medium, said cowl having an inlet and an outlet for the medium to carry oif the heat from the cylinder by conduction as well as by absorption from said cylinder head, said cowl being exposed for cooling purposes to the external air streaming alongside the same, said cowl and cylinder head being madeoi' one piece, a guide wall arranged at, and spaced from the rear portion of the cylinder head to ,form a cooling air duct extending upwardly along the rear cylinder head portion and an outlet passage from said duct for the cooling air extending to the outlet of said cowl.

- FRITZ GOSSLAU. 

